When you need a full-size truck to haul heavy objects, the muscle provided by the 2015 GMC Sierra HD will be more than sufficient. Like the 2015 Chevrolet Silverado 2500 and 3500 HD, the Sierra HD is General Motors' other answer the Ford F-Series and Ram HD trucks. Both the Sierra 2500 and 3500 HD offer you the choice of a 6.0-liter V8 gasoline engine or a 6.6-liter Duramax turbodiesel V8, as well as rear-wheel-drive and 4-wheel-drive configurations. The choices go on from different cab configurations and bed lengths to trim levels. Even though it's not the best heavy-duty truck in its class, the Sierra HD offers plenty of muscle to get the job done.

You'll Like This Car If...

This truck was built to help you tow heavy things on a daily basis, whether it's short or long distances. Whatever the job calls for, the 2015 GMC Sierra will get it done.

You May Not Like This Car If...

There's not a whole lot of daylight between the Sierra and its more mainstream heavy-duty truck cousin, the Silverado. Like the Silverado, the Sierra HD doesn't lead the class in towing numbers, either.

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Consumer Rating

Both the interior and exterior have been redesigned to match that of the Sierra light-duty full-size truck launched last year. The CornerStep bumper and LED taillights in the bed also join the fray.

Driving the Sierra 2500 HD Regular Cab

Driving Impressions
When we spent some time with the 2015 Sierra HD, the drive route consisted mostly of long highway stretches and the miles slipped by thanks to the spacious cabin and...

... a drivetrain that did its part to keep quiet. After a few hours of seat time with and without a trailer in tow, we never felt worse for wear. After we had our fill of towing everyday things like the fifth wheel, we hooked up to a trailer carrying 10,000 pounds and drove GMC's heavy-duty truck up and down a steep grade, rising as high as 5,000 feet above sea level at one point. The full-size Sierra HD demonstrated that it can control just about anything you'll ever need to tow. Each trailer had minimal wag, and the 6-speed Allison automatic transmission (paired with the Duramax) working in conjunction with an exhaust brake kept everything under control going downhill.

Favorite Features

INTERIORAn all-new upright instrument cluster features six gauges and a slew of large, easy-to-use rubberized knobs responsible for various things like climate control and radio volume. Ambient lighting illuminates all of the vital switches in the cabin, making each easier to locate when driving at night.

6.6-LITER DURAMAX ENGINEPaired with a 6-speed Allison automatic transmission, the Duramax turbodiesel engine runs strong and quiet, all while providing power on demand in an even fashion.

2015 GMC Sierra 2500 HD Regular Cab Details

Interior

Major restyling points go to the 2015 GMC Sierra HD interior, and it was achingly overdue. The base model brings basic amenities like a front split-bench seat, air conditioning, and power windows and locks. Move up to the SLE and you'll get features like a leather steering wheel and rubberized vinyl floor mats. The top-tier SLT trim offers everything mentioned plus dual-zone climate control, a high-capacity air cleaner, and a suspension package. Then there's the Denali trim, which is GMC's halo trim across the board. It brings things like contrast stitching, perforated leather seats, and aluminum trim on the instrument panel.

Exterior

Besides the interior, the Sierra HD's exterior styling is a major change for the 2015 model year. Like the interior, the exterior styling of the Sierra HD now more closely reflects that of its light-duty offering. Headlights with LED running lights, a more prominent grille (a common theme in the pickup truck segment, lately), CornerStep rear bumper, and a raised power-dome hood are some noticeable new additions when just looking at the Sierra HD. The same two models, the 2500 and 3500 heavy-duty, are still offered.

Notable Equipment

Standard Equipment

With the base Sierra HD truck, you get a robust V8 engine, antilock disc brakes, air conditioning, and stability control. An automatic locking rear differential is also standard on all Sierra HD trucks with the exception of the 2500 HD base model. Climbing up the trim ladder brings you leather seats, steering-wheel-mounted controls, and Bluetooth. Both Sierra 2500 and 3500 HD models equipped with a Duramax engine also get an all-new electric assist heater, which helps to warm the cabin quickly.

Optional Equipment

The 6.6-liter V8 Duramax turbodiesel engine is, without question, the option to get when outfitting your 2015 Sierra 2500 or 3500 HD. Going with the Duramax engine and 4-wheel drive will save you some major headaches in the future. Other notable options for the 2500 and 3500 truck include a touch-screen navigation system, an EZ-Lift tailgate, and a snow-plow prep package.

Under the Hood

A 6.0-liter V8 gasoline engine or a 6.6-liter Duramax turbodiesel V8 engine provide power to the 2015 GMC Sierra HD. A 6.0-liter V8 powered by compressed natural gas (CNG) is also available, if that's how you roll. Rated at 360 horsepower and 380 lb-ft of torque, the gasoline engine is stout in its own right, but the Duramax diesel is the real star of the show. Power numbers for the 6.6-liter Duramax turbodiesel V8 check in at 397 horsepower and 765 lb-ft of twist. The Duramax engine also brings an exhaust braking system that helps keep the Sierra HD's speed in check going downhill. A 6-speed automatic transmission reports for duty with either engine, but the Duramax gets the added shift-technology benefits of an Allison 6-speed automatic.

If you just want to get into a 2015 GMC Sierra HD, you can do so by spending as little as $35,740. At the other end of the spectrum, if you're looking to drop some serious coin, go with a Sierra Denali 3500 HD crew cab, long box. You won't have any issues clearing the $65,000 mark that way. That number may bring a little sticker shock at first, but it does fall in line with the most plush full-size truck offerings from Ford and Ram. Before buying, be sure to check the Kelley Blue Book Fair Purchase Price to see what others in your area are paying for a 2015 Sierra HD. The resale value of the Sierra HD is also in line with the competition, but opting to go with the Duramax diesel engine will help keep the resale value up.

"Family and friends were shocked when I showed up with a new GMC 1500 SLT Crew Cab in the driveway. My tastes have run towards German sedans and Japanese SUV's with a 1995 Jeep Wrangler being the only domestic product I had bought in 30 years of vehicle ownership. Domestic products had never offered the reliability of the Japanese, the driving dynamics of the Europeans, or the interior quality of either (especially the Europeans).
I had intended to supplement or replace a beloved and dead reliable Toyota 4Runner with 215,000 trouble-free miles with something more modern and upscale, but similarly capable off-road. The Toyota Land Cruiser was one such vehicle that has intrigued me for a long time - with it's DNA of being over-engineered, its understated presence and well-known durability and reliability. In the mean time, I had ridden in an associates 2015 Chevrolet Silverado 1500 LT Crew Cab and was startled by the compliant ride and overall quietness of it in operation. I had not ridden in a pickup in perhaps 10 years. It was far more comfortable than a 2000 Lincoln Navigator that I had owned back in the day. The interior, while not the most "exciting" I have seen, surely was leaps and bounds better the the old Navigator's in quality.
I test drove a Land Cruiser in the following weeks, and while built like the proverbial tank, the ride was not nearly as nice as the Silverado's and the acceleration was not impressive. It quickly became clear that engineering behind the Land Cruiser was very outdated compared to the Chevy's, shown also in the 5-speed transmission and abysmal EPA figures.
For the first time I started to entertain the idea of owning a full-size Pickup or full-size domestic SUV in lieu of an imported midsize or "almost" full-size SUV.
I initially though the Toyota Tundra would be my top candidate. I like the interior of the 1794 edition, but as with the Land Cruiser, it is in need of an update, with a ride and efficiency level that couldn't compare with the Silverado's
I also looked at the Yukon and Tahoe (gorgeous interiors IMO), but the reduction in cargo space from the previous gen and inability to delete the 3rd row seating reduced the desirability for me. The biggest problem in my mind was the astronomical pricing (easily $70k when optioned) of these sleds, putting them in Range Rover/Land Rover and Mercedes GL territory, predicting a level of depreciation I can't stomach.
Long story short, I looked at all the domestic trucks and gravitated to the GMC line. The Ram is supposed to have the best ride (and also is the only one with a 1/2 ton diesel option (which I like), but the aesthetics and interior design are too "gaudy" for me. The Ford F-150 did not feel as good on the road to me as the GMC and one has to go the "eco-boost" route with a 6 or 4 cylinder because the V-8 at this point seems to be in leftover mode.
I know the Sierra and Silverado are identical underneath but I find the styling of the GMC to be more understated and elegant (if one can say that about a truck)
One does not have to venture far on the internet to find out what testers think about the 6.2 litre "Corvette" (almost) engine does to this thing. It is a blast to drive and it is addictive.I ended up purchasing an SLT Crew Cab with the 6.2 and almost all the bells and whistles, putting the price within $2,000 of an equally equiped Denali but having the Z71 Off-Road package that I wanted and which is not available on the Denali. To say this truck has exceeded almost all my expectaions would be an understatment. Other than an occasional rough downshift out of the new 8-speed transmission (which I hope will be fixed with new programming) and rather slow to respond info screen with somewhat second-rate TomTom Navi, I have absolutely no complainants. The interior is beautifully assembled and with high quality components including stitched leather real aluminum (and I am partial to Audi interiors. I can work from my truck with 4G LTE built-in hotspot. Pandora, XM, weather radar and multiple USB ports, DC and 110v outlets all in the front console, make it a pleasure and productive to spend time in this vehicle. What this vehicle most excels at however, is transporting you down the interstate in immense and effortless comfort and silence. Set the air-conditioned leather sears on, cue up the iPhone or Pandora on the Bose stereo and I'm good for a 1,000 mile jaunt. It tracks as straight as any German car I have owned - it drives and handles more like a "car" than either the F150, Ram or Tundra. The ride reminds me of a slightly stiffer version of traditional American luxury cars from the 60's or 70's - due in no small part I'm sure to the 144-inch wheelbase. With triple weather sealing and active noise cancellation, it's as quiet as a 1960's Cadillac, too. With the optional 6.2 litre passing power is instantaneous - with testing showing an under 6-second 0-60. Rest assured 55 to 75 happens in a blink of an eye. And the best part? Over the course of my initial 4,500 miles I have averaged just over 19 MPG calculated manually. Without a headwind (which has a large effect on truck MPG at highway speeds) I average around 22 MPG at 70 MPH and 25 MPG at 60 MPH. This is mind-boggling to me considering this engines feels like a barley-tamed lion underfoot, putting out 420 HO and 460 lb-ft of torque. With V8/V4 technology, direct fuel injection and the 8-speed transmission, there was simply no need to settle for the 5.3
Having grown up in the 60's and 70's in a "GM" family, I had become a hardened critic of their accountant and marketing-consultant designed products - especially since the Roger Smith era of the 80's. The products literally insulted my intelligence. Turn to 2015 - and..this is a great truck. "If" it proves reliable in the long-term, I will have become one of the lost consumers that at least one domestic vehicle maker has brought back into the fold."

"This truck is ever-ready & dependable. The ride, comfort + conveniences (options) are outstanding. No other brand pickup compares to the performance & comfort of this particular model GMC in this price range (perhaps, the Denali) but that seemed a bit too posh to venture out in on jaunts over rugged terrain. A very sensible yet elegant ride - a GMC Professional Grade pickup, indeed! Handling and operation of this 2500HD is a cinch - the installed technology (options) provide added assurance & safety. Gas mileage is as was expected 13 mpg city/19 mpg hwy. No complaints so far."

"I now have 16,000 miles on my 2014 GMC Sierra 1500 Double Cab 4x4 All-Terrain Edition and can give a decent review. I purchased it with 3k miles on it and saved a bundle over the cost of a new one.
This is my first GMC. I have owned Chevy, Dodge, and Ford. My last one being a 2004 F-150 XLT Crew Cab that had almost 200K miles when I gave it to my son. Hopefully this one will do as well.
I looked at all the competition and the GMC seemed to offer the biggest bang for the buck. Mine has the SLE package, 20” wheels and the All-Terrain package which includes most everything I can ever imagine needing and much more luxurious that I am used to in a truck. I have a BMW and this is honestly better equipped.
It has been flawless as far as reliability of the vehicle. No issues at all. My biggest regret is not shopping around for a 5.3 engine version. This one has base 6 cyl and it is lacking for power when trying to haul a heavy trailer. Without a load the engine is fine but if you’re going to haul, definitely look for one with the V8 engine options. Some have complained the headlights are weak but they seem fine to me. The sets seem a bit thin on padding but I have covercraft seat covers that include ¼ foam and they made a huge difference in long trip comfort. The lack of rear vents for the heating and AC seems to be the most foolish design flaw I have noticed. Kids in the back complain and BTW-kids are the only ones that will be comfortable in the back seat of the double-cab version. It’s a tight fit for adults.
My mileage has bested at 23.5 mpg highway over a 350 mile run. My average per tank has been about 17 with mixed driving. My Ford averaged 14. Not a huge improvement but not terrible for a full sized truck.
The bright side for shoppers looking for a used truck, the depreciation hit seems larger than Fords for the first year or two so you can get a good price if you shop around. I live in Virginia and went to Michigan to get this one and the savings we well worth it.
Now if I can just quit spending on accessories…."